a. Field of the Invention
This invention relates to catheters. In particular, the instant invention relates to an irrigated ablation catheter configured to provide an indication of contact force between the catheter and tissue in a body.
b. Background Art
Catheters are used to perform a variety of tasks within human bodies and other bodies including the delivery of medicine and fluids, the removal of bodily fluids and the transport of surgical tools and instruments. In the diagnosis and treatment of atrial fibrillation, for example, catheters may be used to deliver electrodes to the heart for electrophysiological mapping of the surface of the heart and to deliver ablative energy to the surface among other tasks. Catheters are typically routed to a region of interest through the body's vascular system. In a conventional approach, an introducer is inserted through the skin surface and a sheath having an inner diameter greater than the outer diameter of the catheter is threaded through the vasculature to a region of interest. The catheter is then moved longitudinally through the sheath to the region of interest either manually by a clinician or through the use of various types of robotic controls such as electromechanical drive systems.
Many conventional catheters include means for determining the degree of contact between the catheter and tissue and for controlling the catheter in response to the degree of contact. In the case of an electrophysiological mapping catheter, for example, sufficient contact is required to provide meaningful sensor outputs and accurate mapping of the heart. In the case of ablation catheters, sufficient contact is required for effective formation of ablative lesions in the tissue. A variety of mechanisms have been employed in catheters to determine contact force between catheters and tissue including, for example, strain gauges. Conventional mechanisms, however, are relatively complex and require additional components that increase the cost, size, and complexity of the catheter.
The inventor herein has recognized a need for a catheter that will minimize and/or eliminate one or more of the above-identified deficiencies.